<?php
/**
 * Piwik - Open source web analytics
 * 
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 * 
 * @category Piwik_Plugins
 * @package Piwik_VisitorInterest
 */

/**
 * VisitorInterest API lets you access two Visitor Engagement reports: number of visits per number of pages,
 * and number of visits per visit duration.
 * 
 * @package Piwik_VisitorInterest
 */
class Piwik_VisitorInterest_API 
{
	static private $instance = null;
	static public function getInstance()
	{
		if (self::$instance == null)
		{
			self::$instance = new self;
		}
		return self::$instance;
	}

	protected function getDataTable($name, $idSite, $period, $date, $segment, $column = Piwik_Archive::INDEX_NB_VISITS)
	{
		Piwik::checkUserHasViewAccess( $idSite );
		$archive = Piwik_Archive::build($idSite, $period, $date, $segment );
		$dataTable = $archive->getDataTable($name);
		$dataTable->queueFilter('ReplaceColumnNames');
		return $dataTable;
	}
	
	public function getNumberOfVisitsPerVisitDuration( $idSite, $period, $date, $segment = false )
	{
		$dataTable = $this->getDataTable('VisitorInterest_timeGap', $idSite, $period, $date, $segment);
		$dataTable->queueFilter('Sort', array('label', 'asc', true));
		$dataTable->queueFilter('BeautifyTimeRangeLabels', array(
			Piwik_Translate('VisitorInterest_BetweenXYSeconds'),
			Piwik_Translate('VisitorInterest_OneMinute'),
			Piwik_Translate('VisitorInterest_PlusXMin')));
		return $dataTable;
	}

	public function getNumberOfVisitsPerPage( $idSite, $period, $date, $segment = false )
	{
		$dataTable = $this->getDataTable('VisitorInterest_pageGap', $idSite, $period, $date, $segment);
		$dataTable->queueFilter('Sort', array('label', 'asc', true));
		$dataTable->queueFilter('BeautifyRangeLabels', array(
			Piwik_Translate('VisitorInterest_OnePage'),
			Piwik_Translate('VisitorInterest_NPages')));
		return $dataTable;
	}
	
	/**
	 * Returns a DataTable that associates counts of days (N) with the count of visits that
	 * occurred within N days of the last visit.
	 *
	 * @param int $idSite The site to select data from.
	 * @param string $period The period type.
	 * @param string $date The date type.
	 * @param string|bool $segment The segment.
	 * @return Piwik_DataTable the archived report data.
	 */
	public function getNumberOfVisitsByDaysSinceLast( $idSite, $period, $date, $segment = false )
	{
		$recordName = 'VisitorInterest_daysSinceLastVisit';
		$dataTable = $this->getDataTable(
			$recordName, $idSite, $period, $date, $segment, Piwik_Archive::INDEX_NB_VISITS);

		$dataTable->queueFilter('BeautifyRangeLabels', array(
			Piwik_Translate('General_OneDay'), Piwik_Translate('General_NDays')));
		
		return $dataTable;
	}
	
	/**
	 * Returns a DataTable that associates ranges of visit numbers with the count of visits
	 * whose visit number falls within those ranges.
	 *
	 * @param int $idSite The site to select data from.
	 * @param string $period The period type.
	 * @param string $date The date type.
	 * @param string|bool $segment The segment.
	 * @return Piwik_DataTable the archived report data.
	 */
	public function getNumberOfVisitsByVisitCount( $idSite, $period, $date, $segment = false )
	{
		$dataTable = $this->getDataTable(
			'VisitorInterest_visitsByVisitCount', $idSite, $period, $date, $segment, Piwik_Archive::INDEX_NB_VISITS);

		$dataTable->queueFilter('BeautifyRangeLabels', array(
			Piwik_Translate('General_OneVisit'), Piwik_Translate('General_NVisits')));

		// add visit percent column
		self::addVisitsPercentColumn($dataTable);

		return $dataTable;
	}

	/**
	 * Utility function that adds a visit percent column to a data table,
	 * regardless of whether the data table is an data table array or just
	 * a data table.
	 *
	 * @param Piwik_DataTable $dataTable The data table to modify.
	 */
	private static function addVisitsPercentColumn( $dataTable )
	{
		if ($dataTable instanceof Piwik_DataTable_Array)
		{
			foreach($dataTable->getArray() as $table)
			{
				self::addVisitsPercentColumn($table);
			}
		}
		else
		{
			$totalVisits = array_sum($dataTable->getColumn(Piwik_Archive::INDEX_NB_VISITS));
			$dataTable->queueFilter('ColumnCallbackAddColumnPercentage', array(
				'nb_visits_percentage', 'nb_visits', $totalVisits));
		}
	}
}
